Yes of course ! The guide will be available on the forum dedicated to KeyDuino (http://keyduino.forumsactifs.com/). And we will also support the community on the forum by answering questions directly.
Tutorials with different levels of complexity will be also available on the forum. Each tutorial will help you to build a complete cool project.
There are two main modifications:
- TX & RX (D0, D1) of Leonardo are connected to the PN532 and thus aren't available.
To be allowed to access UART, D14 & D16 are put in place of TX / RX ; you then just have to use "Software.Serial" to connect to any shield through UART.
- ISCP connector was moved to let space for the NFC antenna. Shields using SPI communication through this connector must then be connected via cables.
For this kind of complicated projects, it is fundamental to have solid basics in Electronics. KeyDuino allows this authentication, but for more evolved actions like starting a car, you have to add actuators (e.g. electronic locks). To use these actuators, you will at least need to weld and connect them to KeyDuino.
Don't see the answer to your question? Ask the project creator directly.